This invention relates to a data processing system and more particularly to a system particularly adopted to store, process and distribute digital data including both textual data and digitized voice signals. Such systems should be capable of handling a multiplicity of voice inputs and outputs, preferably over telephone lines, and have a capacity for storing a substantial quantity of digitized voice signals. Further, such a system should have the capacity for correlating such stored voice signals with digital signals representing textual data and commands so that functions such as "voice mail", i.e., storing and forwarding voice messages, centralized dictation and "voice annotation of text", i.e., correlated storage of verbal comments and corrections with stored textual material, so that word processing operator may update the text from voice.
While systems which have some integrated capacity for handling both voice signals and textual data are known, none have as yet provided the full range of voice functions described above in a manner which is compatible and readily intergratable with conventional local data processing networks. A particular problem has been that the high data rates necessary to handle multiple simultaneous digitized voice signals create a need for a multiple processor architecture, while the need for complex and frequent communications between processors, required to maintain coordination between various tasks involving both digitized voice signals and textual data, tended to place a large communications burden on each processor and so reduce its effective computing power. Even in systems where separate busses were provided for voice data and digital data use of the digital data bus for interprocessor communications still significantly reduced effective processing power.
In other systems where memory and processors shared the same bus, access by one processor to memory would necessarily interrupt the operations of other processors requiring access to memory, while other architectures where each processor had only private memory and the bus carried only I/O communications between processors were too slow when blocks of data had to be transferred between processor memories.
Further prior art bus structures were normally adapted for a particular processor or family of processors and choice of a bus structure tended to limit a system and further developments of that system to a particular family of processors.
Thus, it is an object of the subject invention to provide a data processing system having the capability to receive, store, process and transmit digital data were such data may be either textual data or digitized voice signals.
It is a further object of the subject invention to provide such a system where digital data and digitized voice signals may be stored in a correlated manner so as to provide for functions such as "voice annotation of text".
It is also an object of the subject invention to provide such a system using a multiprocessor architecture where the interprocessor communications burden is substantially reduced.